| 24 Feb 2026
Respecting the boundaries: balancing climate adaptation and Earth system resilience
Abstract. Anthropogenic climate change necessitates not only rapid climate mitigation but also widespread adaptation. It is common knowledge that climate adaptation cannot replace and must not derail mitigation efforts. Yet surprisingly little is known about the existing pressures of climate adaptation on the Earth system. The Planetary Boundaries framework sets biogeophysical limits for critical Earth system processes. In an explorative analysis, existing interactions of climate adaptation with proxies for the Planetary Boundaries are investigated. Linking research from various domains into an attribution analysis, it is found climate adaptation currently contributes ~25.56 percent of annual greenhouse gas emissions and ~74.08 percent of annual human freshwater withdrawals. Climate adaptation even affects the stratosphere: the ozone hole is to a considerable degree an unintended consequence of climate adaptation. Climate change already drives some of these impacts. However, fuelled by factors such as economic and population growth, the majority of these effects would likely also have occurred under Holocene climates. This proves both the importance and the urgency of respecting safe boundaries when accelerating global climate adaptation.
Competing interests: At least one of the (co-)authors is a member of the editorial board of Earth System Dynamics.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
This article looks at the Earth system impacts of measures referred to as ‘climate adaptation’. These measures include modifying the flow of water, building and maintaining residential structures, and refrigeration. They discuss general findings of the literature and provide approximate estimates for the CO2e emissions associated with the measures.
I feel this is a useful article that makes some valuable points. However I think it needs major revision prior to publication. This revision should clarify the language, to prevent dangerous misinterpretation, and should also restructure the text to reduce repetition and focus the message.
Most importantly, the authors need to take greater care in distinguishing between 1. the adaptation to local climate for any reason, and 2. adapting to climate change. The latter is what is typically meant by ‘climate adaptation’, yet the authors are inconsistent in their use of the term, sometimes applying it to one and sometimes the other. For the purposes of this article I might suggest they differentiate ‘local climate adaptation’ vs. ‘climate-change adaptation’, where the second is a component of the first.
Once the authors have decided how to deal with this, the abstract needs to be significantly rewritten, to first introduce the reader to the idea of what is meant by adapting to the local climate, so that the meaning of the ’26%’ of emissions and ’74%’ of freshwater are clear. Otherwise the reader will assume that these amounts are for adaptation to climate change, which would be incorrect. Many parts of the manuscript will need to be adjusted to be consistent with this (too numerous to list here).
The manuscript could also be greatly improved by reducing repetition (especially in section 1) and focusing on the novel findings.
Specific comments:
- I didn’t find the four functional mechanisms (line 120) very intuitive. It was hard for me to understand why the first two would be called ‘flow’ and “boundary’, given what is meant by them. Also, I wondered why is a green wall would be functionally different than a cement wall? However perhaps these are better explained in the cited paper (Ott et al., 2025 submitted)?
- calling all refrigeration 'climate adaptation' seems like a stretch, since much of it is to preserve food... is it true that's what being done here?
- Line 171 phrase starting ‘However, one should also account…’ was very hard to understand.
- The disagreement with Abajian et al., 2025 seems important - I’d request more detail regarding this comparison. Is it true that they only included CO2? What specifically is wrong with their analysis?